Lamp construction



Oct. 7, 1947, c. E. TsoURos l2,428,479

LAMP CONSTRUCTION Filed Sept. 22, 1944 I N V EN TOR. y fans afzaf'mma 24Y wrom/5K5 Patented Oct. 7, 1947 LAIVIP CONSTRUCTION Constantine E.Tsouros, Brooklyn, N.'Y., assigner to E. A. Laboratories, Inc.,Brooklyn, N. Y., a corporation of New York Application September 22,1944, Serial No. 555,242

2y Claims. 1

This invention relates to improvements in electric lamp construction andparticularly to an improved means for securing the lens and reflector ofa lamp in proper relationship to-a casing.

The invention is particularly applicable to electric lamps of thesealed-beam type, in which the lamp and reflector are a single unit,although it will be apparent that it is useful with conventional lampforms. Sealed-beam lamps, however, are becoming increasingly popular inexposed installations, such as automobile, marine, and aircraft service,and the invention will be described in association with such lamps.

Sealed-beam lamps comprise a reflector portion and a lamp portion bondedtogether and evacuated after the lamp filament is installed therein. Thejoint between the reflector and lens portions is a continuouscircumferential bead, having a shoulder for cooperation with an abutmentor rim portion on the lamp casing for securernent thereagainst. Lampmanufacturers have found it commercially impracticable to hold the widthof the bead to an exact dimension and it is standard practice for suchlamps to have a tolerance plus or minus .035 in the overall width of thebead.

It is common practice to retain such lamps within the housing or casingby means of a clamping ring, bezel or the like. Because of the total of.070 variation in the width of the bead, it has been diicult properly tosecure the lamps within their casings by the presently used `types ofholding rings.

The present invention contemplates an improved holding ring, made ofmaterial such as spring steel. In cross section, the wall of the ring iscurved, the concave surface being innermost. The ring is adapted to gripthe casing and to engage a forward shoulder or abutment of the bead ofthe lamp, thereby holding the lamp in position. The width of the ring isso proportioned that it will properly hold within the casing a lamphaving the minimum width of bead. When lamps having greater than minimumthickness are encountered, the inherent resiliency of the holding ringpermits increasing its width suitably to accommodate the increased widthof the lamp joint. Hence, lamps of minimum and maximum dimensions areproperly maintained in operative relationship with their casings.

It is an object of the invention, therefore to provide an improved meansfor securing a lamp within a casing.

It is another object of the invention to provide (Cl. 24E-41.5)

Z an improved retaining ring for lamps, which may be distended toaccommodate lamp structures having greater than normal dimension.

It is another object of the invention to provide an improved lampembodying a sealed-beam lamp, a casing therefor, and an improvedretaining ring for holdingv said lamp within said casing.

In the accompanying drawings:

Fig. 1 is an elevation partly in section of one type of lamp embodyingthe present invention;

Fig. 2 is a side elevation in section of the retaining ring;

Fig` 3 is a front elevation of one form of retaining ring; and

Fig. 4 is a front elevation of a other form of retaining ringj,

Referring to the drawings, a lamp illustrated in Fig. 1 comprises acasing I0, a lamp II and a retaining ring l2. The casing may be ofco-nventional configuration, usually substantially hemispherical and isprovided. adjacent its equator with a shoulder I4 which may result froma rolled groove I5.

The lamp I I is illustratively of the sealed-beam type and includes areflector portion I6 and a lens portion Il. As is well known, thesealedbearn lamps are characterized by a bead-like peripheral joint I8at which the reflector and lens portions are secured together. The jointI8 is usually so conflgurated that a rear, wall 20 serves as the surfaceupon which the lamp is supported, and a forward wall 2| provides ashoulder or abutment which may be gripped by a suitable retainer forholding the lamp within the casing. Practical considerations ofmanufacture of the lamps render it impossible to maintain the widthbetween Walls ZI! and 2| to precise dimension and the manufacturers ofsuch lamps have standardized on a tolerance of plus or minus .O3-5 inwidth between the respective walls.

Lamps of the sealed-beam type generally afford no means of securement toa housing other than with a retaining ring or equivalent. By reason ofthe aforementioned variation in the thickness at the joint I8however,difficulty has been experienced in adequately securing the lamp withinthe casing by means of a standardized retaining ring. Such retainingrings will not adjust to the diierences in the thickness of the lamp atthe location of its attachment to the housing. It has thereforepreviously been necessary individually to fit a ring to a particularlamp.

The retaining ring I2 of the present invention is spun or otherwiseformed of spring material such as relatively thin cold rolled steel. The

portion of ancentral wall is deeply concave. The rear or right hand wall22 of the ring, as Viewed in Fig 2, is preferably slightly re-entrant;said Wall ts within and tightly grips the wall of the groove l providedin the housing I0. The opposite wall 23 is substantially flat andengages the forward shoulder 2| of the lamp. Y

' The "normal "rclaxed-uwidth `of thez ring r r2i-is such that'withftheminimum thickness of the joint I8, the lamp is tightly, but resiliently,held against shoulder lll. When a lamp having/la maximum thickness ofjoint is encounteredsaid thickness being usually a matter of .070greater than the minimum thickness, zthejresi'liency; of ring l2 permitsit to expand' to embracersuch maximum thickness. A standard retainingring, therefore, serves for all lampsnvithin the usual commercialtolerance of bead width.

In some lamp constructions, it is practicable t0 have the ring I2 devoidof joint, there being cenoughfresilienyinfthe ringe and in the `lampscasingfl `to;permit,theeedge 22 of ;.thei'ring,to cam over. the-outeredge -of.- Vthe casingaand snap .11i-nto thegfgroovef t5. The; reentrantedge 22V-of the ffringapermits this. Fori-larger; lamps, iin which thematerial. of theecasing- I O-and/or; the ring l 2 :may f fbe -ofheavieri-gafuge, the ring :may fbegsplit,Y i at its bottom andprovidedswithftabs44,24 through @which .a'screwfZ- -or'fequiva-lentgmay;pass, for, se- '.curement bya' nut orlikedevice.

:InzsuchA form, the relaxeddiameterofithe ring I2 will be sufcient topass over the ibeadorjoint ofzthe lamp,;and:over ltheifrontfedgetof: thelamp casing. After positioning, the Screw: 25a-maybe made up: to;tighten the' ring.

Whereas it is obviciusthatffamongfthe; several Aeobjects ,of the:inventionaas specifically' aforenoted care iachieved, ,z it :isfa'pparent that nnumerous fchangesin:construction :and rearrangements of-i therpartsamightrbe 4resortedftorwithoui;v departing fromth'e.lspiritfof? thelinvention vas defined' by fthe'claims.

I claim:

1.' In j combinationfgwithfa lamp of i the sealed ebeam type" having;a'pe'ripheral bead' delineating i rbetween] the?lensiandf-rfiectorsections of said Vflarrrn3 a-flampi easingofcircularcrosssection subastanti alrlyequal'jinl 'diameter to the.diameterv of rfsaid lamp'- immediately'behind i said bead, said scasing'bei-ng -'formed :adjacent its `forward -edge awith 2a fde'epfcircumference: groove4V providing "a :substantiallyi fiat"-inner-=casingwallT terminating -inaan iinwardly extending radial shoulder, saidvwallifand= sai'dshoulderfdningffapocket' toY receivef and "engage :withfsad lamp; and -a` lamp 35 i'nto. the casing.

retaining ring of thin springablenaterial having a concave inner wallterminating in a radially extending inwardly curved rear Wall engageablewith said casing groove and a radially extending substantially flatfront wall engageablel With the forward wall of said lamp bead; thenormal width of said ring measured from edge to edge of the 'frespectivewalls being'slessithanthe minimumv -standard Width; of the bead of`a"sealed beam lamp, and said ring being expansible to accom- .modatethe maximum standardV bead width of `v`saidelamp While retaining thecurvature of the rear wall of said ring. f

'2.IIn.combination' With a lamp of the sealed` 1.5ebeamftype'having anexternal peripheral bead d'elineating between the lens and reflectorsec- .,tions thereof and a substantially cylindrical, relatively short,Wall structure rearwardly of said bead; a=casing having a front wallportion to relatively snugly receive said cylindrical wall and hav` f aretaining ring of thin, springable materialhaving,- a stili?rradial-lya:I extending Wall: seating 4vwithin ssaid'fgroovelandasubstantially radially extending K .-'frontfawallengageablef with thefforward surface -Q'said cylindricaltbead; therelaxedwidth ofsa-id 30*'ringrmeasured' frornsedgecto;V edgeof'its respective @Walls :beingless-than fthe r-rrrinimum standard @width-ofthe saidzbea'dsofarsea'ledebeamlamp; the

forward =wallifof=:saidrretainin'g: ring 'being elastic, so as toresilientlylurgefthesaidlamp rearwardly eoNsTAN'rINEfn TsoURos.

REFERENGES? CITED Tlief following references are or" record; in the'ilaoft this Y"patent:

PUNITED. sfr-ATESf-PATENTs v 1VNumber 1 Name Y 7Date l 13313,'716 Mazzeo`Aug; 19,`v 1919 111681,1042, r`#Kuen Aug.` 14, 1928 i 1,884,076lMi'chel' 'Oct. 25,'1932 2,138,077 Taylor et al Nov. 29,- 1938'22,267,707 Bosten fDec. 30,1941 V2,363,147 j-Roper Nov, 21, 1944'172253328 "'-Krapp 'Aug` 26,'1941 '22715425 4I-Iarris Jan. 27, l1942FOREIGN .PATENTS Number Country Date j :A733025 Germany i'1929

